The Pirates returned home from a nine-game road trip Thursday tied with St. Louis for first place in the National League Central Division — and for the best record in the major leagues.

And they’ve done so despite ...

• Getting little offensive production out of right field. Travis Snider is hitting .230 and Garrett Jones has six home runs.

• Having their three top starting pitchers entering the season — A.J. Burnett, Wandy Rodriguez and James McDonald — on the disabled list.

• Having their third baseman, Pedro Alvarez, hitting below .200 for the first two months of the season.

• Shortstop Clint Barmes being forced to the bench because of a lack of production.

• Top utility player Brandon Inge collecting two hits in 32 at-bats over a period of weeks.

So ... how is this team winning?

Reason No. 1, of course, is pitching.

Going into this weekend’s Milwaukee series, the Pirates carried a staff ERA of 3.36, trailing only division rivals St. Louis and Cincinnati among National League clubs.

Jason Grilli has emerged as the league’s top closer, Mark Melancon its top setup man.

Jeff Locke is 7-1 with an ERA hovering around 2.00. This guy had one career win in the big leagues entering this season.

Francisco Liriano is 6-3 and an early candidate for Comeback Player of the Year honors. His career was in doubt during the offseason.

Gerrit Cole is called up and wins his first four decisions. Brandon Cumpton comes up and gives the team two quality starts in emergency situations. Before the season started, no one even heard of the guy.

So what’s the common denominator here?

Russell Martin.

There’s your Pirates’ MVP for the first half of 2013.

Pirate pitchers have put together a 3.12 ERA with Martin behind the plate. Only the Cardinals’ Yadier Molina (3.11) has a better ERA among major league catchers thus far.

Martin has thrown out 13 of the 27 runners trying to steal against him. Remember how big a sore spot that was last year?

This guy has single-handedly taken care of that issue.

Besides all of that, he’s been a contributor at the plate, belting eight home runs, hitting near .260 and producing from different positions in the batting order. And Martin draws walks.

Few Pirate hitters have done that over the past few years.

When the Bucs shelled out $14 million for two years to sign Martin early in the free agency period, the general reaction across baseball and Pittsburgh was that they paid too much.

Now it seems Martin has become a bargain.

The stabilizing influence he has had on this team and the pitching staff cannot be overstated.

Whether the Pirates stay in the race remains to be seen.

Regardless, in Martin’s case, the Bucs received bang for their bucks.

John Enrietto is sports editor of the Butler Eagle